Slide rack clamp apparatus

ABSTRACT

A slide rack clamp apparatus that secures a slide rack in a digital slide scanning apparatus. In an embodiment, the slide rack clamp apparatus includes an upper clamp and a lower clamp. Each clamp comprises one or more clamp projections, which are configured to engage one or more recesses in engagement surfaces of a plurality of different slide racks from different manufacturers. The lower clamp is driven by a motor along a linear axis to engage the lower clamp projections with the one or more slide rack recesses of the bottom surface of the slide rack. The motor drives the lower clamp and the engaged slide rack upward to engage the one or more slide rack recesses of the top surface of the slide rack with the clamp projections of the upper clamp to fully engage the slide rack between the upper clamp and the lower clamp.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/624,158, filed on Dec. 18, 2019, which is a national stage entry ofInternational Patent App. No. PCT/US2018/063464, filed on Nov. 30, 2018,which claims priority to U.S. Provisional Patent App. No. 62/593,138,filed on Nov. 30, 2017, which are all hereby incorporated herein byreference as if set forth in full.

BACKGROUND Field of the Invention

The present invention relates generally to a digital slide scanningapparatus (e.g., for pathology) and, more particularly, to an internalslide rack clamp apparatus that secures a slide rack for internaltransport within the digital slide scanning apparatus.

Related Art

Digital pathology is an image-based information environment which isenabled by computer technology that allows for the management ofinformation generated from a physical slide. Digital pathology isenabled in part by virtual microscopy, which is the practice of scanninga specimen on a physical glass slide and creating a digital slide imagethat can be stored, viewed, managed, and analyzed on a computer monitor.With the capability of imaging an entire glass slide, the field ofdigital pathology has exploded and is currently regarded as one of themost promising avenues of diagnostic medicine in order to achieve evenbetter, faster, and cheaper diagnosis, prognosis, and prediction ofimportant diseases, such as cancer.

Some digital slide scanning apparatuses have been modified to hold aplurality of slide racks so that the digital slide scanning apparatuscan sequentially process tens or hundreds of glass slides withoutinterruption. However, the conveyance of individual glass slides fromthe slide rack to the scanning stage remains a significant challenge.Therefore, what is needed is a system and method that overcomes thesesignificant problems found in the conventional systems described above.

SUMMARY

Accordingly, in an embodiment, a slide rack clamp apparatus is describedherein that secures a slide rack, internal to a digital slide scanningapparatus, for conveyance to and from a scanning stage within thedigital slide scanning apparatus. The slide rack clamp apparatus mayinclude an upper clamp and a lower clamp. Each of the upper clamp andthe lower clamp include one or more clamp projections. The one or moreclamp projections may be configured to engage one or more slide rackrecesses of a plurality of different slide racks from a plurality ofdifferent slide rack manufacturers. The lower clamp is driven by a motoralong a linear axis to engage the lower clamp projections with the oneor more slide rack recesses of the lower surface of the slide rack. Themotor drives the lower clamp and the engaged slide rack upward to engagethe one or more slide rack recesses of the upper surface of the sliderack with the clamp projections of the upper clamp, so as to fullyengage the slide rack between the upper clamp and the lower clamp.

In an embodiment, a slide rack clamp apparatus comprises: a lower clampcomprising an engagement surface and two or more lower clamp projectionsextending outward from the engagement surface, the lower clampprojections configured to engage one or more slide rack recesses in abottom surface of a slide rack; an upper clamp comprising an engagementsurface and two or more upper clamp projections extending outward fromthe engagement surface, the upper clamp projections configured to engageone or more slide rack recesses in a top surface of the slide rack; anda motor configured to drive the lower clamp along a linear axis toengage the lower clamp projections with the one or more slide rackrecesses in the bottom surface of the slide rack, and, subsequent toengaging the lower clamp with the slide rack, drive the lower clampfarther along the linear axis to engage the one or more slide rackrecesses in the top surface of the slide rack with the upper clampprojections so as to fully engage the slide rack between the lower clampand the upper clamp. The two or more clamp projections of the lowerclamp and/or upper clamp may extend a fixed distance from the engagementsurface of the respective clamp. At least one (e.g., all) of the two ormore projections of the lower clamp and/or upper clamp is spring-loaded,such that it remains extended when engaged with one of the one or moreslide rack recesses in the respective surface of the slide rack, andrecedes into a recess of the engagement surface of the respective clampwhen directly engaged with the respective surface of the slide rack.

In an embodiment, the upper clamp is configured to provide resistanceagainst the motor, while the motor is driving the lower clamp along thelinear axis, when the slide rack is fully engaged between the lowerclamp and the upper clamp. The resistance may comprise the weight of theupper clamp.

In an embodiment, the lower clamp projections and/or upper clampprojections are configured to prevent X-Y movement of the slide rack, ina plane that is orthogonal to a longitudinal axis of the clampprojections, when engaged with the one or more slide rack recesses inthe respective surface of the slide rack. Each of the two or more lowerclamp projections may correspond to an identical one of the two or moreupper clamp projections. In addition, each of the two or more lowerclamp projections may be aligned, along a longitudinal axis of the lowerclamp projection, with the identical one of the two or more upper clampprojections.

In an embodiment, each of the two or more lower clamp projections andeach of the two or more upper clamp projections comprise a beveled edgeand/or are positionally fixed with respect to the engagement surface oftheir respective clamps. A profile of the two or more lower clampprojections and a profile of the two or more upper clamp projections maybe aligned with two or more different profiles of recesses for two ormore different slide racks, such that each of the two or more lowerclamp projections and the two or more upper clamp projections fit withinat least one recess in each of the two or more different slide racks.

In an embodiment, a digital slide scanning apparatus comprises: theslide rack clamp apparatus of claim 1; and an assembly for loading aslide from the slide rack onto a scanning stage and unloading a slidefrom the scanning stage into the slide rack.

In an embodiment, a method is disclosed that comprises: controlling amotor to drive a lower clamp, comprising an engagement surface and twoor more lower clamp projections extending outward from the engagementsurface, toward a bottom surface of a slide rack; engaging the two ormore lower clamp projections with one or more slide rack recesses in thebottom surface of the slide rack; subsequent to engaging the two or morelower clamp projections with the one or more slide rack recesses in thebottom surface of the slide rack, controlling the motor to drive thelower clamp and the slide rack toward an upper clamp, comprising a sliderack engagement surface and two or more upper clamp projectionsextending outward from the engagement surface; engaging one or moreslide rack recesses in the top surface of the slide rack with the two ormore upper clamp projections to fully engage the slide rack between thelower clamp and the upper clamp; and controlling the motor to drive thefully engaged slide rack toward a scanning stage within a digital slidescanning apparatus. Controlling the motor to drive the lower clamp maycomprise driving the lower clamp along a linear axis.

Other features and advantages of the present invention will become morereadily apparent to those of ordinary skill in the art after reviewingthe following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The structure and operation of the present invention will be understoodfrom a review of the following detailed description and the accompanyingdrawings in which like reference numerals refer to like parts and inwhich:

FIG. 1A is a top-view diagram illustrating an example slide rack from afirst manufacturer with glass slides, according to an embodiment;

FIG. 1B is a top-view diagram illustrating an example slide rack from asecond manufacturer with glass slides, according to an embodiment;

FIG. 2A is a perspective-view diagram illustrating a slide rack clampapparatus with an example slide rack from a first manufacturer,according to an embodiment;

FIG. 2B is a perspective-view diagram illustrating a slide rack clampapparatus with an example slide rack from a second manufacturer,according to an embodiment;

FIG. 2C is a perspective-view diagram illustrating the engagementpositions of the projections of an upper clamp with respect to a sliderack from a first manufacturer, according to an embodiment;

FIG. 2D is a perspective-view diagram illustrating the engagementpositions of the projections of an upper clamp with respect to a sliderack from a second manufacturer, according to an embodiment of theinvention;

FIG. 3A is a perspective-view diagram illustrating partial engagement ofa slide rack, according to an embodiment;

FIG. 3B is a perspective-view diagram illustrating full engagement of aslide rack, according to an embodiment;

FIG. 3C is a perspective-view diagram illustrating partial engagement ofa slide rack, according to an embodiment;

FIG. 3D is a perspective-view diagram illustrating full engagement of aslide rack, according to an embodiment;

FIG. 4A is a block diagram illustrating an example processor-enableddevice that may be used in connection with various embodiments describedherein;

FIG. 4B is a block diagram illustrating an example line scan camerahaving a single linear array, according to an embodiment;

FIG. 4C is a block diagram illustrating an example line scan camerahaving three linear arrays, according to an embodiment; and

FIG. 4D is a block diagram illustrating an example line scan camerahaving a plurality of linear arrays, according to an embodiment.

DETAILED DESCRIPTION

Certain embodiments disclosed herein provide for a slide rack clampapparatus that engages a lower and upper surface of a slide rack from aplurality of manufacturers, and secures the slide rack and the glassslides therein for internal transport within a digital slide scanningapparatus. After reading this description it will become apparent to oneskilled in the art how to implement the invention in various alternativeembodiments and alternative applications. However, although variousembodiments of the present invention will be described herein, it isunderstood that these embodiments are presented by way of example only,and not limitation. As such, this detailed description of variousalternative embodiments should not be construed to limit the scope orbreadth of the present invention as set forth in the appended claims.

1. Example Slide Racks

FIG. 1A is a top-view diagram illustrating an example slide rack 100Afrom a first manufacturer with glass slides 585, according to anembodiment. In the illustrated embodiment, the slide rack 100A comprisestwo slide rack recesses 120A and 120B in the top surface 110A of theslide rack 100A. Additionally, the top surface 110A of the slide rack100A comprises a bevel along one or more of the internal and/or externaledges of the top surface 110A of the slide rack 100A. Specifically, therecesses 120A and 120B are each formed with a beveled internal edge 122Aand 122B, respectively. The external edges of the top surface 110A arealso shown with a bevel. In alternative embodiments, different portionsof the internal and/or external edges of the top surface 110A of theslide rack 100A may be beveled (e.g., transitioning from the top surface110A to side surfaces of the slide rack 100A at a slope) and/orunbeveled (e.g., transitioning from the top surface 110A to sidesurfaces of the slide rack 100A at a right angle).

FIG. 1B is a top-view diagram illustrating an example slide rack 100Bfrom a second manufacturer with glass slides 585, according to anembodiment. In the illustrated embodiment, the slide rack 100B comprisesa single slide rack recess 120C in the top surface 110B of the sliderack 100B. Additionally, the top surface 110B of the slide rack 100Bcomprises a bevel along one or more of the internal and/or externaledges of the top surface 110B of the slide rack 100B. Specifically, therecess 120C is formed with a beveled internal edge 122C. However, theexternal edge of the top surface 110B is shown as unbeveled. Inalternative embodiments, different portions of the internal and/orexternal edges of the top surface 110B of the slide rack 100B may bebeveled and/or unbeveled.

Although not shown, the bottom surfaces of the slide racks 100A and 100Bmay be similar or identical to the respective top surfaces 110A and110B. For example, the bottom surface of the slide rack 100A maycomprise the same recesses 120A and 120B, as well as the same bevelededges 122A and 122B. Similarly, the bottom surface of the slide rack100B may comprise the same recess 120C, as well as the same beveled edge122C.

2. Example Slide Rack Clamp Apparatus

FIG. 2A is a perspective-view diagram illustrating a slide rack clampapparatus with an example slide rack 100A from a first manufacturer,according to an embodiment. FIG. 2B is a perspective-view diagramillustrating the same slide rack clamp apparatus with an example sliderack 100B from a second manufacturer, according to an embodiment. In theillustrated embodiment, the slide rack clamp apparatus comprises anupper clamp 200 and a lower clamp 250.

In an embodiment, the upper clamp 200 comprises an engagement surface202 (not visible in FIGS. 2A and 2B due to the orientation of the upperclamp 200) configured to engage at least one engagement surface of theslide rack 100 (e.g., the top surface 110). Similarly, the lower clamp250 comprises an engagement surface 252 configured to engage at leastone engagement surface of the slide rack 100 (e.g., the bottom surfaceof slide rack 100). Each of the engagement surface 202 of the upperclamp 200 and the engagement surface 252 of the lower clamp 250 has aplurality of projections extending outward from the respectiveengagement surface. For example, in the illustrated embodiment, theengagement surface 202 of the upper clamp 200 has a plurality ofdownwardly extending projections 204. Similarly, the engagement surface252 of the lower clamp 250 has a plurality of upwardly extendingprojections 254. The plurality of projections on either engagementsurface of the slide rack clamp apparatus may be the same or differentin shape and/or size, and the plurality of projections on the engagementsurface of one clamp may be the same or different in number, shape,and/or size than the plurality of projections on the engagement surfaceof the other clamp. In the illustrated example, the upper clamp 200 hastwo projections 204A and 204B, which are different shapes and sizes fromeach other, and the lower clamp 250 has two projections 254A and 254B,which are different shapes and sizes from each other. However, theprojection 204A on the upper clamp 200 is identical to the projection254A on the lower clamp 250, and the projection 204B on the upper clamp200 is identical to the projection 254B on the lower clamp 250. In otherwords, the plurality of projections on the same engagement surface aredifferent from each other, but the set of projections on one engagementsurface are the same as the set of projections on the other engagementsurface. As shown, each pair of identical projections may be alignedwith each other (i.e., mirror each other) along the longitudinal axisbetween the upper clamp 200 and the lower clamp 250.

In an embodiment, one or more edges of the projections 204 and 254 arebeveled. For example, in the illustrated embodiment, the projections204A and 204B of the upper clamp 200 have beveled edges 206A and 206B,respectively. Similarly, the projections 254A and 254B of the lowerclamp 250 have beveled edges 256A and 256B, respectively.Advantageously, the beveled edges 206 of the projections 204 mayfacilitate alignment of the upper clamp 200 with the top surface 110 ofthe slide rack 100 when the upper clamp 200 engages the slide rack 100,and the beveled edges 256 of the projections 254 may facilitatealignment of the lower clamp 250 with the bottom surface of the sliderack 100 when the lower clamp 250 engages the slide rack 100.

In an embodiment, the one or more beveled edges of the projectionsmirror the recess(es) in the corresponding engagement surfaces of one ormore slide racks 100, which may or may not also have beveled edges. Forexample, in the illustrated embodiment, the beveled edge 206A of theprojection 204A of the upper clamp 200 mirrors the internal bevelededges 122A of recess 120A and 122C of recess 120C in the top surfaces110 of both slide racks 100A and 100B, respectively, and the bevelededge 206B of the projection 204B of the upper clamp 200 mirrors theinternal beveled edges 122B of recess 120B and 122C of recess 120C inthe top surfaces 110 of both slide racks 100A and 100B, respectively.Similarly, the beveled edge 256A of the projection 254A of the lowerclamp 250 mirrors the internal beveled edges 122A of recess 120A and122C of recess 120C in the bottom surfaces of both slide racks 100A and100B, respectively, and the beveled edge 256B of the projection 254B ofthe lower clamp 250 mirrors the internal beveled edges 122B of recess120B and 122C of recess 120C in the bottom surfaces of both slide rack100A and 100B, respectively. In an alternative embodiment, one or morebeveled edges of the projections do not mirror the correspondingengagement surfaces of the slide rack 100.

FIG. 2C is a perspective-view diagram illustrating the engagementpositions of the projections 204 of the upper clamp 200 with respect toa slide rack 100A from a first manufacturer, according to an embodiment.In the illustrated embodiment, the plurality of projections 204 on theengagement surface 202 of the upper clamp 200 are configured to engagethe two slide rack recesses 120A and 120B of the first slide rack 100Aby fitting within recesses 120A and 120B. Specifically, projection 204Afits within recess 120A in the top surface 110A of the slide rack 100A,and projection 204B fits within the recess 120B in the top surface 110Aof the slide rack 100A. Although not shown, the projections 254A and254B of the lower clamp 250 fit within recesses 120A and 120B on thebottom surface of the slide rack 100A, in an identical manner.

FIG. 2D is a perspective-view diagram illustrating the engagementpositions of the projections 204 of the upper clamp 200 with respect toa slide rack 100B from a second manufacturer, according to anembodiment. In the illustrated embodiment, the plurality of projections204 on the engagement surface 202 of the upper clamp 200 are configuredto engage the single slide rack recess 120C of the second slide rack100B by fitting within recess 120C. Specifically, projection 204A fitswithin a first region of the recess 120C in the top surface 110B of theslide rack 100B, and projection 204B fits within a second region of thesame recess 120C in the top surface 110B of the slide rack 100B.Although not shown, the projections 254A and 254B of the lower clamp 250fit within recess 120C on the bottom surface of the slide rack 100B, inan identical manner.

As illustrated, the upper clamp 200 and lower clamp 250 are configuredto be usable with (i.e., support engagement with) two or more differentslide racks 100A and 100B. This is achieved by configuring the profileof the plurality of projections 204 and 254, such that the cross-sectionof each projection 204 and 254 (i.e., within a cut plane that isorthogonal to the longitudinal axis of the projections) fits within arecess 120 in the top and/or bottom engagement surfaces of each sliderack 100 that is to be supported by the slide rack clamp apparatus. Inthis manner, the slide rack clamp apparatus can be configured to supportany number of slide racks 100 (e.g., two, three, five, ten, twenty,fifty, one hundred, etc.).

In the illustrated embodiment, the plurality of projections 204 and 254are fixed such that they do not move. Advantageously, engagement of theprojections 204 and 254 with the slide rack recess(es) 120 in the topsurface 110 and bottom surface of each slide rack 100, prevents X-Ymovement of the slide rack 100. Specifically, insertion of theprojections 204 and 254 within recess(es) 120 of the top and bottomsurfaces prevent the slide rack 100 from sliding or shifting within aplane that is orthogonal to the longitudinal axis of the projections 204and 254.

In an alternative embodiment, one or more projections 204 and/or 254, onone or both of the upper clamp 200 and lower clamp 250, may beconfigured to move. For example, a projection may slide along itslongitudinal axis, such that it recedes into a recess of its respectiveclamp when force is applied to the open end of the projection. Theprojection may be biased towards extending from (as opposed to recedinginto) the engagement surface 202 or 252. This bias may be accomplishedusing a spring, within the recess in the clamp into which the projectionis configured to recede, to push, along the longitudinal axis of theprojection, on the closed end of the projection that is opposite theopen end of the projection (e.g., which engages the slide rack 100).When a force is applied to the open end of the projection, the springcompresses, such that the projection recedes into the clamp, and, whenthe force is removed, the spring decompresses, thereby pushing theprojection out of the recess in the clamp so as to extend from theclamp. In this manner, if the projection does not fit within any recess120 of the engagement surface of the slide rack 100, the force of thedirect engagement with the engagement surface of the slide rack 100 willpush the projection into its recess in the clamp, so that the projectionis out of the way. Any projections which do fit within a recess 120 ofthe engagement surface of the slide rack 100 do not recede into theclamp, and therefore, will extend into the recess 120 so as to preventX-Y movement of the slide rack 100. An advantage of using one or moremovable projections is that the profile of the plurality of projections204 and 254 does not have to correspond to the profile of the recesses120 in each of the slide racks 100 to be supported, since projectionswhich do not fit within a recess 120 of the engagement surface of theslide rack 100 are forced into their corresponding recesses in the clampso as to be out of the way. A disadvantage of using movable projections,as opposed to fixed projections, is the addition of mechanicalcomplexity (e.g., springs and recesses within the clamp). It should beunderstood that, in an embodiment, some projections may be fixed (e.g.,a projection which corresponds to a recess 120 in every supported sliderack 100), while others may be movable (e.g., a projection whichcorresponds to a recess 120 in only a partial subset of the supportedslide racks 100).

FIG. 3A is a perspective-view diagram illustrating partial engagement ofa slide rack 100, according to an embodiment. Specifically, in aninitial state, the slide rack 100 is engaged with the lower clamp 250,but not yet engaged with the upper clamp 200. In an embodiment, a motor(not shown) is configured to drive the lower clamp 250 along a linearaxis (e.g., that is parallel to the longitudinal axis of the projections254 and orthogonal to the plane of the engagement surface 252) to engagethe projections 254 of the lower clamp 250 with the one or more sliderack recesses 120 in the bottom surface of the slide rack 100. The upperclamp 200 is positioned along the same linear axis, and the projections204 are aligned with the projections 254 within the linear axis. Thus,as the motor drives the lower clamp 250 along the linear axis, while thelower clamp 250 is engaged with the slide rack 100, the top surface 110of the slide rack 100 is brought into engagement with the upper clamp200. In an embodiment, the motor may drive the lower clamp 250 along thelinear axis until it detects resistance from the engagement surface 202of the upper clamp 200 (e.g., produced by the weight of the upper clamp200 against the top surface 110 of the slide rack 100).

FIG. 3B is a perspective-view diagram illustrating full engagement of aslide rack 100, according to an embodiment. Specifically, the slide rack100 is engaged with both the lower clamp 250 and the upper clamp 200. Inthe illustrated embodiment, following the initial, partial engagementbetween the lower clamp 250 and the slide rack 100 illustrated in FIG.3A, the motor has driven the lower clamp 250, as well as the slide rack100 due to the partial engagement, to additionally engage the upperclamp 200. Accordingly, the slide rack 100 is now fully engaged betweenthe upper clamp 200 and the lower clamp 250. In addition, the slide rack100 is prevented from X-Y-Z movement with respect to the slide rackclamp apparatus, because the slide rack 100 is fixed, along all threeaxes, between the upper clamp 200 and the lower clamp 250 by virtue ofthe projections 204 and 254. The same motor and/or a different motor maybe configured to drive the slide rack clamp apparatus, in this fullyengaged state, so as to move the slide rack 100 to a scanning stage ofthe digital slide scanning apparatus.

While the lower clamp 250 is described as being driven towards the upperclamp 200, it should be understood that, in an alternative embodiment,the upper clamp 200 could initially engage with the slide rack 100 andthen drive the slide rack 100 along the linear axis to engage with thelower clamp 250. As another alternative, the slide rack 100 can bepositioned on the lower clamp 250 (e.g., by a slide rack carousel,operator, etc.) so as to initially engage with the lower clamp 250without the need of the motor, and then the motor could drive the upperclamp 200 along the linear axis to engage with the top surface 110 ofthe slide rack 100. As yet another alternative, the slide rack 100 canbe positioned to initially engage with the upper clamp 200 without theneed of the motor, and then the motor could drive the lower clamp 250along the linear axis to engage with the bottom surface of the sliderack 100. Other manners and sequences of initial and full engagement arealso contemplated.

FIG. 3C is a perspective-view diagram illustrating partial engagement ofa slide rack 100, according to an embodiment. Specifically, in aninitial state, the slide rack 100 is engaged with the lower clamp 250,but not yet engaged with the upper clamp 200. In an embodiment, a motor(not shown) is configured to drive the lower clamp 250 along a linearaxis (e.g., that is parallel to the longitudinal axis of the projections254 and orthogonal to the plane of the engagement surface 252) guided bya linear axis rail 350 to engage the projections 254 of the lower clamp250 with the one or more slide rack recesses 120 in the bottom surfaceof the slide rack 100. The upper clamp 200 is guided by a linear axisrail 300 and is positioned along the same linear axis as the lower clamp250, and the projections 204 are aligned with the projections 254 withinthe linear axis. Thus, as the motor drives the lower clamp 250 along thelinear axis rail 350 to drive the lower clamp 250 along the linear axis,while the lower clamp 250 is engaged with the slide rack 100, the topsurface 110 of the slide rack 100 is brought into engagement with theupper clamp 200. In an embodiment, the motor may drive the lower clamp250 along the linear axis rail 350 to drive the lower clamp 250 alongthe linear axis until it detects resistance from the engagement surface202 of the upper clamp 200 (e.g., produced by the weight of the upperclamp 200 against the top surface 110 of the slide rack 100).

FIG. 3D is a perspective-view diagram illustrating full engagement of aslide rack 100, according to an embodiment. Specifically, the slide rack100 is engaged with both the lower clamp 250 and the upper clamp 200. Inthe illustrated embodiment, following the initial, partial engagementbetween the lower clamp 250 and the slide rack 100 illustrated in FIG.3C, the motor has driven the lower clamp 250, as well as the slide rack100 due to the partial engagement, to additionally engage the upperclamp 200. Accordingly, the slide rack 100 is now fully engaged betweenthe upper clamp 200 and the lower clamp 250. In addition, the slide rack100 is prevented from X-Y-Z movement with respect to the slide rackclamp apparatus, because the slide rack 100 is fixed, along all threeaxes, between the upper clamp 200 and the lower clamp 250 by virtue ofthe projections 204 and 254. The same motor and/or a different motor maybe configured to drive the slide rack clamp apparatus along therespective linear axis rails 300 and 350 in this fully engaged state, soas to move the slide rack 100 along the linear axis to a scanning stageof the digital slide scanning apparatus.

While the lower clamp 250 is described as being driven towards the upperclamp 200, it should be understood that, in an alternative embodiment,the upper clamp 200 could initially engage with the slide rack 100 andthen drive the slide rack 100 along the respective linear axis rails 300and 350 to move the slide rack 100 along the linear axis to engage withthe lower clamp 250. As another alternative, the slide rack 100 can bepositioned on the lower clamp 250 (e.g., by a slide rack carousel,operator, etc.) so as to initially engage with the lower clamp 250without the need of the motor, and then the motor could drive the upperclamp 200 along the linear axis rail 300 to engage with the top surface110 of the slide rack 100. As yet another alternative, the slide rack100 can be positioned to initially engage with the upper clamp 200without the need of the motor, and then the motor could drive the lowerclamp 250 along the linear axis rail 300 to engage with the bottomsurface of the slide rack 100. Other manners and sequences of initialand full engagement are also contemplated.

3. Example Embodiments

In an embodiment, a slide rack clamp apparatus includes a lower clamphaving a slide rack engagement surface and two or more lower clampprojections extending upward from the slide rack engagement surface. Thelower clamp projections are configured to engage one or more slide rackrecesses in a bottom surface of a slide rack. The slide rack clampapparatus also includes an upper clamp having a slide rack engagementsurface and two or more upper clamp projections extending downward fromthe slide rack engagement surface. The upper clamp projections areconfigured to engage one or more slide rack recesses in a top surface ofa slide rack. The slide rack clamp apparatus also includes a first motorconfigured to drive the lower clamp along a linear axis to engage thelower clamp projections with the one or more slide rack recesses in thebottom surface of the slide rack. The first motor is also configured to,subsequent to engaging the lower clamp with the slide rack, drive thelower clamp along the linear axis to engage the upper clamp projectionswith the one or more slide rack recesses in the top surface of the sliderack to fully engage the slide rack between the lower clamp and theupper clamp.

In an embodiment, the two or more lower clamp projections of the sliderack clamp apparatus are fixed to the lower clamp slide rack engagementsurface and extend a fixed distance from the lower clamp slide rackengagement surface.

In an embodiment, the two or more lower clamp projections of the sliderack clamp apparatus are not fixed and are configured to remain extendedinto the one or more slide rack recesses in the bottom surface of theslide rack or recede into the lower clamp slide rack engagement surfacewhen engaged with the bottom surface of the slide rack. For example, thetwo or more lower clamp projections may be spring-loaded.

In an embodiment, the two or more upper clamp projections of the sliderack clamp apparatus are fixed to the upper clamp slide rack engagementsurface and extend a fixed distance from the upper clamp slide rackengagement surface.

In an embodiment, the two or more upper clamp projections of the sliderack clamp apparatus are not fixed and are configured to remain extendedinto the one or more slide rack recesses in the top surface of the sliderack or recede into the upper clamp slide rack engagement surface whenengaged with the top surface of the slide rack. For example, the two ormore upper clamp projections may be spring-loaded.

In an embodiment, the upper clamp is configured to provide resistanceagainst the first motor driving the lower clamp along the linear axiswhen the slide rack is fully engaged between the lower clamp and theupper clamp. For example, the resistance may be provided by the weightof the upper clamp. The resistance may also be mechanical or magnetic inalternative embodiments. Advantageously, the resistance secures theslide rack between the upper and lower clamps during transport.

In an embodiment, the lower clamp projections are further configured toprevent X-Y movement of the slide rack when engaged with the one or moreslide rack recesses in the bottom surface of the slide rack.

In an embodiment, the upper clamp projections are further configured toprevent X-Y movement of the slide rack when engaged with the one or moreslide rack recesses in the top surface of the slide rack.

In an embodiment, a method of securing a slide rack within a digitalslide scanner apparatus comprises using a motor to drive a lower clamp,having a slide rack engagement surface and two or more lower clampprojections extending upward from the slide rack engagement surface,toward a bottom surface of a slide rack and engaging the two or morelower clamp projections with one or more slide rack recesses in thebottom surface of the slide rack. The method also includes, subsequentto engaging the two or more lower clamp projections with one or moreslide rack recesses in the bottom surface of the slide rack, using themotor to drive the lower clamp and the slide rack toward an upper clamp,having a slide rack engagement surface and two or more upper clampprojections extending downward from the slide rack engagement surface,and engaging the two or more upper clamp projections with one or moreslide rack recesses in the top surface of the slide rack. The methodalso includes using the motor to drive the fully engaged slide racktoward a scanning stage within the digital slide scanner apparatus. Inan embodiment of the method, using the motor to drive the lower clampincludes driving the lower clamp along a linear axis.

4. Example Digital Slide Scanning Apparatus

FIG. 4A is a block diagram illustrating an example processor-enableddevice 550 that may be used in connection with various embodimentsdescribed herein. Alternative forms of the device 550 may also be usedas will be understood by the skilled artisan. In the illustratedembodiment, the device 550 is presented as a digital imaging device(also referred to as a digital slide scanning apparatus, digital slidescanner, scanner, scanner system, digital imaging device, etc.) thatcomprises one or more processors 555, one or more memories 565, one ormore motion controllers 570, one or more interface systems 575, one ormore movable stages 580 that each support one or more glass slides 585with one or more samples 590, one or more illumination systems 595 thatilluminate the sample, one or more objective lenses 600 that each definean optical path 605 that travels along an optical axis, one or moreobjective lens positioners 630, one or more optional epi-illuminationsystems 635 (e.g., included in a fluorescence scanner system), one ormore focusing optics 610, one or more line scan cameras 615 and/or oneor more area scan cameras 620, each of which define a separate field ofview 625 on the sample 590 and/or glass slide 585. The various elementsof the scanner system 550 are communicatively coupled via one or morecommunication busses 560. Although there may be one or more of each ofthe various elements of the scanner system 550, for simplicity in thedescription, these elements will be described in the singular exceptwhen needed to be described in the plural to convey the appropriateinformation.

The one or more processors 555 may include, for example, a centralprocessing unit (CPU) and a separate graphics processing unit (GPU)capable of processing instructions in parallel, or the one or moreprocessors 555 may include a multi-core processor capable of processinginstructions in parallel. Additional separate processors may also beprovided to control particular components or perform particularfunctions such as image processing. For example, additional processorsmay include an auxiliary processor to manage data input, an auxiliaryprocessor to perform floating point mathematical operations, aspecial-purpose processor having an architecture suitable for fastexecution of signal processing algorithms (e.g., digital-signalprocessor), a slave processor subordinate to the main processor (e.g.,back-end processor), an additional processor for controlling the linescan camera 615, the stage 580, the objective lens 225, and/or a display(not shown). Such additional processors may be separate discreteprocessors or may be integrated with the processor 555. The one or moreprocessors may be configured to control the motors of the clampapparatus, and thereby control the overall workflow of the digitalimaging device 550.

The memory 565 provides storage of data and instructions for programsthat can be executed by the processor 555. The memory 565 may includeone or more volatile and/or non-volatile computer-readable storagemediums that store the data and instructions, including, for example, arandom access memory, a read only memory, a hard disk drive, a removablestorage drive, and/or the like. The processor 555 is configured toexecute instructions that are stored in memory 565 and communicate viacommunication bus 560 with the various elements of the scanner system550 to carry out the overall function of the scanner system 550.

The one or more communication busses 560 may include a communication bus560 that is configured to convey analog electrical signals and mayinclude a communication bus 560 that is configured to convey digitaldata. Accordingly, communications from the processor 555, the motioncontroller 570, and/or the interface system 575 via the one or morecommunication busses 560 may include both electrical signals and digitaldata. The processor 555, the motion controller 570, and/or the interfacesystem 575 may also be configured to communicate with one or more of thevarious elements of the scanning system 550 via a wireless communicationlink.

The motion control system 570 is configured to precisely control andcoordinate X-Y-Z movement of the stage 580 and the objective lens 600(e.g., via the objective lens positioner 630). The motion control system570 is also configured to control movement of any other moving part inthe scanner system 550. For example, in a fluorescence scannerembodiment, the motion control system 570 is configured to coordinatemovement of optical filters and the like in the epi-illumination system635.

The interface system 575 allows the scanner system 550 to interface withother systems and human operators. For example, the interface system 575may include a user interface to provide information directly to anoperator and/or to allow direct input from an operator. The interfacesystem 575 is also configured to facilitate communication and datatransfer between the scanning system 550 and one or more externaldevices that are directly connected (e.g., a printer, removable storagemedium, etc.) or external devices, such as an image server system, anoperator station, a user station, and an administrative server system,that are connected to the scanner system 550 via a network (not shown).

The illumination system 595 is configured to illuminate a portion of thesample 590. The illumination system 595 may include, for example, alight source and illumination optics. The light source could be avariable intensity halogen light source with a concave reflective mirrorto maximize light output and a KG-1 filter to suppress heat. The lightsource could also be any type of arc-lamp, laser, or other source oflight. In an embodiment, the illumination system 595 illuminates thesample 590 in transmission mode such that the line scan camera 615and/or area scan camera 620 sense optical energy that is transmittedthrough the sample 590. Alternatively or additionally, the illuminationsystem 595 may be configured to illuminate the sample 590 in reflectionmode such that the line scan camera 615 and/or area scan camera 620sense optical energy that is reflected from the sample 590. Overall, theillumination system 595 is configured to be suitable for interrogationof the microscopic sample 590 in any known mode of optical microscopy.

In an embodiment, the scanner system 550 optionally includes anepi-illumination system 635 to optimize the scanner system 550 forfluorescence scanning. Fluorescence scanning is the scanning of samples590 that include fluorescence molecules, which are photon sensitivemolecules that can absorb light at a specific wavelength (excitation).These photon sensitive molecules also emit light at a higher wavelength(emission). Because the efficiency of this photoluminescence phenomenonis very low, the amount of emitted light is often very low. This lowamount of emitted light typically frustrates conventional techniques forscanning and digitizing the sample 590 (e.g., transmission modemicroscopy). Advantageously, in an optional fluorescence scanner systemembodiment of the scanner system 550, use of a line scan camera 615 thatincludes multiple linear sensor arrays (e.g., a time delay integration(TDI) line scan camera) increases the sensitivity to light of the linescan camera by exposing the same area of the sample 590 to each of themultiple linear sensor arrays of the line scan camera 615. This isparticularly useful when scanning faint fluorescence samples with lowemitted light.

Accordingly, in a fluorescence scanner system embodiment, the line scancamera 615 is preferably a monochrome TDI line scan camera.Advantageously, monochrome images are ideal in fluorescence microscopybecause they provide a more accurate representation of the actualsignals from the various channels present on the sample. As will beunderstood by those skilled in the art, a fluorescence sample 590 can belabeled with multiple florescence dyes that emit light at differentwavelengths, which are also referred to as “channels.”

Furthermore, because the low and high end signal levels of variousfluorescence samples present a wide spectrum of wavelengths for the linescan camera 615 to sense, it is desirable for the low and high endsignal levels that the line scan camera 615 can sense to be similarlywide. Accordingly, in a fluorescence scanner embodiment, a line scancamera 615 used in the fluorescence scanning system 550 is a monochrome10-bit 64-linear-array TDI line scan camera. It should be noted that avariety of bit depths for the line scan camera 615 can be employed foruse with a fluorescence scanner embodiment of the scanning system 550.

The movable stage 580 is configured for precise X-Y axes movement undercontrol of the processor 555 or the motion controller 570. The movablestage may also be configured for movement in a Z axis under control ofthe processor 555 or the motion controller 570. The moveable stage isconfigured to position the sample in a desired location during imagedata capture by the line scan camera 615 and/or the area scan camera.The moveable stage is also configured to accelerate the sample 590 in ascanning direction to a substantially constant velocity and thenmaintain the substantially constant velocity during image data captureby the line scan camera 615. In an embodiment, the scanner system 550may employ a high-precision and tightly coordinated X-Y grid to aid inthe location of the sample 590 on the movable stage 580. In anembodiment, the movable stage 580 is a linear motor based X-Y stage withhigh precision encoders employed on both the X and the Y axes. Forexample, very precise nanometer encoders can be used on the axis in thescanning direction and on the axis that is in the directionperpendicular to the scanning direction and on the same plane as thescanning direction. The stage is also configured to support the glassslide 585 upon which the sample 590 is disposed.

The sample 590 can be anything that may be interrogated by opticalmicroscopy. For example, a glass microscope slide 585 is frequently usedas a viewing substrate for specimens that include tissues and cells,chromosomes, DNA, protein, blood, bone marrow, urine, bacteria, beads,biopsy materials, or any other type of biological material or substancethat is either dead or alive, stained or unstained, labeled orunlabeled. The sample 590 may also be an array of any type of DNA orDNA-related material such as cDNA, RNA, or protein that is deposited onany type of slide or other substrate, including any and all samplescommonly known as microarrays. The sample 590 may be a microtiter plate,for example a 96-well plate. Other examples of the sample 590 includeintegrated circuit boards, electrophoresis records, petri dishes, film,semiconductor materials, forensic materials, and machined parts.

Objective lens 600 is mounted on the objective positioner 630 which, inan embodiment, may employ a very precise linear motor to move theobjective lens 600 along the optical axis defined by the objective lens600. For example, the linear motor of the objective lens positioner 630may include a 50 nanometer encoder. The relative positions of the stage580 and the objective lens 600 in X-Y-Z axes are coordinated andcontrolled in a closed loop manner using motion controller 570 under thecontrol of the processor 555 that employs memory 565 for storinginformation and instructions, including the computer-executableprogrammed steps for overall operation of the scanning system 550.

In an embodiment, the objective lens 600 is a plan apochromatic (“APO”)infinity-corrected objective with a numerical aperture corresponding tothe highest spatial resolution desirable, where the objective lens 600is suitable for transmission mode illumination microscopy, reflectionmode illumination microscopy, and/or epi-illumination mode fluorescencemicroscopy (e.g., an Olympus 40X, 0.75NA or 20X, 0.75 NA).Advantageously, objective lens 600 is capable of correcting forchromatic and spherical aberrations. Because objective lens 600 isinfinity corrected, focusing optics 610 can be placed in the opticalpath 605 above the objective lens 600 where the light beam passingthrough the objective lens becomes a collimated light beam. The focusingoptics 610 focus the optical signal captured by the objective lens 600onto the light-responsive elements of the line scan camera 615 and/orthe area scan camera 620 and may include optical components such asfilters, magnification changer lenses, and/or the like. The objectivelens 600 combined with focusing optics 610 provides the totalmagnification for the scanning system 550. In an embodiment, thefocusing optics 610 may contain a tube lens and an optional 2×magnification changer. Advantageously, the 2× magnification changerallows a native 20× objective lens 600 to scan the sample 590 at 40×magnification.

The line scan camera 615 comprises at least one linear array of pictureelements (“pixels”). The line scan camera may be monochrome or color.Color line scan cameras typically have at least three linear arrays,while monochrome line scan cameras may have a single linear array orplural linear arrays. Any type of singular or plural linear array,whether packaged as part of a camera or custom-integrated into animaging electronic module, can also be used. For example, a3-linear-array (“red-green-blue” or “RGB”) color line scan camera or a96-linear-array monochrome TDI may also be used. TDI line scan camerastypically provide a substantially better signal-to-noise ratio (SNR) inthe output signal by summing intensity data from previously imagedregions of a specimen, yielding an increase in the SNR that is inproportion to the square-root of the number of integration stages. TDIline scan cameras comprise multiple linear arrays. For example, TDI linescan cameras are available with 24, 32, 48, 64, 96, or even more lineararrays. The scanner system 550 also supports linear arrays that aremanufactured in a variety of formats including some with 512 pixels,some with 1,024 pixels, and others having as many as 4,096 pixels.Similarly, linear arrays with a variety of pixel sizes can also be usedin the scanner system 550. The salient requirement for the selection ofany type of line scan camera 615 is that the motion of the stage 580 canbe synchronized with the line rate of the line scan camera 615, so thatthe stage 580 can be in motion with respect to the line scan camera 615during the digital image capture of the sample 590.

The image data generated by the line scan camera 615 is stored in aportion of the memory 565 and processed by the processor 555 to generatea contiguous digital image of at least a portion of the sample 590. Thecontiguous digital image can be further processed by the processor 555,and the processed contiguous digital image can also be stored in thememory 565.

In an embodiment with two or more line scan cameras 615, at least one ofthe line scan cameras 615 can be configured to function as a focusingsensor that operates in combination with at least one of the line scancameras 615 that is configured to function as an imaging sensor. Thefocusing sensor can be logically positioned on the same optical axis asthe imaging sensor, or the focusing sensor may be logically positionedbefore or after the imaging sensor with respect to the scanningdirection of the scanner system 550. In an embodiment with at least oneline scan camera 615 functioning as a focusing sensor, the image datagenerated by the focusing sensor is stored in a portion of the memory565 and processed by the one or more processors 555 to generate focusinformation to allow the scanner system 550 to adjust the relativedistance between the sample 590 and the objective lens 600 to maintainfocus on the sample during scanning. Additionally, in an embodiment, theat least one line scan camera 615 functioning as a focusing sensor maybe oriented such that each of a plurality of individual pixels of thefocusing sensor is positioned at a different logical height along theoptical path 605.

In operation, the various components of the scanner system 550 and theprogrammed modules stored in memory 565 enable automatic scanning anddigitizing of the sample 590, which is disposed on a glass slide 585.The glass slide 585 is securely placed on the movable stage 580 of thescanner system 550 for scanning the sample 590. Under control of theprocessor 555, the movable stage 580 accelerates the sample 590 to asubstantially constant velocity for sensing by the line scan camera 615,where the speed of the stage is synchronized with the line rate of theline scan camera 615. After scanning a stripe of image data, the movablestage 580 decelerates and brings the sample 590 to a substantiallycomplete stop. The movable stage 580 then moves orthogonal to thescanning direction to position the sample 590 for scanning of asubsequent stripe of image data (e.g., an adjacent stripe). Additionalstripes are subsequently scanned until an entire portion of the sample590 or the entire sample 590 is scanned.

For example, during digital scanning of the sample 590, a contiguousdigital image of the sample 590 is acquired as a plurality of contiguousfields of view that are combined together to form an image stripe. Aplurality of adjacent image stripes are similarly combined together toform a contiguous digital image of a portion of the sample 590 or theentire sample 590. The scanning of the sample 590 may include acquiringvertical image stripes or horizontal image stripes. The scanning of thesample 590 may be either top-to-bottom, bottom-to-top, or both(bi-directional) and may start at any point on the sample.Alternatively, the scanning of the sample 590 may be eitherleft-to-right, right-to-left, or both (bi-directional) and may start atany point on the sample. Additionally, it is not necessary that imagestripes be acquired in an adjacent or contiguous manner. Furthermore,the resulting image of the sample 590 may be an image of the entiresample 590 or only a portion of the sample 590.

In an embodiment, computer-executable instructions (e.g., programmedmodules or other software) are stored in the memory 565 and, whenexecuted, enable the scanning system 550 to perform the variousfunctions described herein. In this description, the term“computer-readable storage medium” is used to refer to any media used tostore and provide computer executable instructions to the scanningsystem 550 for execution by the processor 555. Examples of these mediainclude memory 565 and any removable or external storage medium (notshown) communicatively coupled with the scanning system 550 eitherdirectly or indirectly (e.g., via a network).

FIG. 4B illustrates a line scan camera having a single linear array 640,which may be implemented as a charge coupled device (“CCD”) array. Thesingle linear array 640 comprises a plurality of individual pixels 645.In the illustrated embodiment, the single linear array 640 has 4,096pixels. In alternative embodiments, linear array 640 may have more orfewer pixels. For example, common formats of linear arrays include 512,1,024, and 4,096 pixels. The pixels 645 are arranged in a linear fashionto define a field of view 625 for the linear array 640. The size of thefield of view varies in accordance with the magnification of the scannersystem 550.

FIG. 4C illustrates a line scan camera having three linear arrays, eachof which may be implemented as a CCD array. The three linear arrayscombine to form a color array 650. In an embodiment, each individuallinear array in the color array 650 detects a different color intensity(e.g., red, green, or blue). The color image data from each individuallinear array in the color array 650 is combined to form a single fieldof view 625 of color image data.

FIG. 4D illustrates a line scan camera having a plurality of lineararrays, each of which may be implemented as a CCD array. The pluralityof linear arrays combine to form a TDI array 655. Advantageously, a TDIline scan camera may provide a substantially better SNR in its outputsignal by summing intensity data from previously imaged regions of aspecimen, yielding an increase in the SNR that is in proportion to thesquare root of the number of linear arrays (also referred to asintegration stages). A TDI line scan camera may comprise a largervariety of numbers of linear arrays. For example, common formats of TDIline scan cameras include 24, 32, 48, 64, 96, 120 and even more lineararrays.

The above description of the disclosed embodiments is provided to enableany person skilled in the art to make or use the invention. Variousmodifications to these embodiments will be readily apparent to thoseskilled in the art, and the generic principles described herein can beapplied to other embodiments without departing from the spirit or scopeof the invention. Thus, it is to be understood that the description anddrawings presented herein represent a presently preferred embodiment ofthe invention and are therefore representative of the subject matterwhich is broadly contemplated by the present invention. It is furtherunderstood that the scope of the present invention fully encompassesother embodiments that may become obvious to those skilled in the artand that the scope of the present invention is accordingly not limited.

What is claimed is:
 1. A slide rack clamp apparatus comprising: a firstclamp comprising a first engagement surface and one or more first clampprojections extending outward from the first engagement surface, the oneor more first clamp projections configured to engage one or more sliderack recesses in a first surface of a slide rack; a second clampcomprising a second engagement surface and one or more second clampprojections extending outward from the second engagement surface, theone or more second clamp projections configured to engage one or moreslide rack recesses in a second surface of the slide rack; and a motorconfigured to drive one or both of the first clamp and the second clampalong a linear axis to engage the one or more first clamp projectionswith the one or more slide rack recesses in the first surface of theslide rack and engage the one or more second clamp projections with theone or more slide rack recesses in the second surface of the slide rack.2. The slide rack clamp apparatus of claim 1, wherein the one or morefirst clamp projections extend a fixed distance from the firstengagement surface of the first clamp.
 3. The slide rack clamp apparatusof claim 1, wherein the one or more second clamp projections extend afixed distance from the second engagement surface of the second clamp.4. The slide rack clamp apparatus of claim 1, wherein at least one ofthe one or more first clamp projections is spring-loaded, such that theat least one first clamp projection remains extended when engaged withone of the one or more slide rack recesses in the first surface of theslide rack, and recedes into a recess of the first engagement surface ofthe first clamp when directly engaged with the first surface of theslide rack.
 5. The slide rack clamp apparatus of claim 4, wherein theone or more first clamp projections comprise a plurality of first clampprojections that are each spring-loaded.
 6. The slide rack clampapparatus of claim 1, wherein at least one of the one or more secondclamp projections is spring-loaded, such that the at least one secondclamp projection remains extended when engaged with one of the one ormore slide rack recesses in the second surface of the slide rack, andrecedes into a recess of the second engagement surface of the secondclamp when directly engaged with the second surface of the slide rack.7. The slide rack clamp apparatus of claim 6, wherein the one or moresecond clamp projections comprise a plurality of second clampprojections that are each spring-loaded.
 8. The slide rack clampapparatus of claim 1, wherein the motor is configured to drive the firstclamp along the linear axis, and wherein the second clamp is configuredto provide resistance against the motor, while the motor is driving thefirst clamp along the linear axis, when the slide rack is fully engagedbetween the first clamp and the second clamp.
 9. The slide rack clampapparatus of claim 8, wherein the resistance comprises a weight of thesecond clamp.
 10. The slide rack clamp apparatus of claim 1, wherein theone or more first clamp projections are configured to prevent X-Ymovement of the slide rack, in a plane that is orthogonal to alongitudinal axis of the one or more first clamp projections, whenengaged with the one or more slide rack recesses in the first surface ofthe slide rack.
 11. The slide rack clamp apparatus of claim 1, whereinthe one or more second clamp projections are configured to prevent X-Ymovement of the slide rack, in a plane that is orthogonal to alongitudinal axis of the one or more second clamp projections, whenengaged with the one or more slide rack recesses in the second surfaceof the slide rack.
 12. The slide rack clamp apparatus of claim 1,wherein each of the one or more first clamp projections corresponds toan identical one of the one or more second clamp projections.
 13. Theslide rack clamp apparatus of claim 12, wherein each of the one or morefirst clamp projections is aligned, along a longitudinal axis of thefirst clamp projection, with the identical one of the one or more secondclamp projections.
 14. The slide rack clamp apparatus of claim 1,wherein each of the one or more first clamp projections and each of theone or more second clamp projections comprises a beveled edge.
 15. Theslide rack clamp apparatus of claim 1, wherein the one or more firstclamp projections and the one or more second clamp projections arepositionally fixed.
 16. The slide rack clamp apparatus of claim 15,wherein a profile of the one or more first clamp projections and aprofile of the one or more second clamp projections are aligned with twoor more different profiles of recesses for two or more different slideracks, such that each of the one or more first clamp projections and theone or more second clamp projections fits within at least one recess ineach of the two or more different slide racks.
 17. A digital slidescanning apparatus comprising: the slide rack clamp apparatus of claim1; and an assembly for loading a slide from the slide rack onto ascanning stage and unloading a slide from the scanning stage into theslide rack.
 18. A method comprising: controlling a motor to drive afirst clamp, comprising a first engagement surface and one or more firstclamp projections extending outward from the first engagement surface,toward a first surface of a slide rack; engaging the one or more firstclamp projections with one or more slide rack recesses in the firstsurface of the slide rack; subsequent to engaging the one or more firstclamp projections with the one or more slide rack recesses in the firstsurface of the slide rack, controlling the motor to drive the firstclamp and the slide rack toward a second clamp, comprising a secondengagement surface and one or more second clamp projections extendingoutward from the second engagement surface; engaging one or more sliderack recesses in the second surface of the slide rack with the one ormore second clamp projections to fully engage the slide rack between thefirst clamp and the second clamp; and controlling the motor to drive thefully engaged slide rack toward a scanning stage within a digital slidescanning apparatus.
 19. The method of claim 18, wherein controlling themotor to drive the first clamp comprises driving the first clamp along alinear axis.